BACKGROUND OF THE INVENTION
Field of the Invention
[0001] The present invention relates to a display device using a chip on film (COF) operating
with a low driving voltage.
Background of the Related Art
[0002] Lately, display devices having wide image areas are the trend of the times. The display
devices have much more data and scan lines in order to improve image quality.
[0003] However, if the number of the scan lines is increased to improve the image quality
of the display device having a simple matrix structure, there are many limitations
on driving the display device.
[0004] FIG. 1 illustrates a diagram of a display device using a COF according to a related
art.
[0005] Referring to FIG. 1, data lines are connected straight to a chip on film(hereinafter
abbreviated COF) from a display panel. And, scan lines, which are arranged on left
and right sides of the display panel respectively, extend from the display panel with
forming a curve so as to be coupled with the COF.
[0006] As mentioned in the above explanation, the scan lines forming curves from both sides
of the display panel extend longer than the data lines. Such a structure results in
increasing line resistance of the scan lines and further delays a signal response.
[0007] In display devices such as EL(electro-luminescence), LED(light emitting diode), FED(field
emission display) and the like, the line-resistance of-the scan lines has a close
relation to the driving voltage of the display devices.
[0008] Namely, if the line resistance of the scan lines increases, the driving voltage thereof
increases as well. Thus, the line resistance of the display device having a low driving
voltage is a major issue.
SUMMARY OF THE INVENTION
[0009] Accordingly, the present invention is directed to a display device using a COF that
substantially obviates -one or more problems due to limitations and disadvantages
of the related art.
[0010] An object of the present invention is to provide a display device using a COF enabling
to reduce line resistance of scan and data lines in a display device.
[0011] Additional advantages, objects, and features of the invention will be set forth in
part in the description which follows and in part will become apparent to those having
ordinary skill in the art upon examination of the following or may be learned from
practice of the invention. The objectives and other advantages of the invention may
be realized and attained by the structure particularly pointed out in the written
description and claims hereof as well as the appended drawings.
[0012] To achieve these objects and other advantages and in accordance with the purpose
of the invention, as embodied and broadly described herein, a display device using
a COF according to the present invention includes a display panel, a COF having a
connection part on which the display channel is placed and a chip part on which a
chip is placed, data and scan lines extending from the display panel, scan line connection
lines on the connection part, the scan line connection lines connecting the scan lines
electrically to the COF, and data line connection lines on the connection part, the
data line connection lines connecting the data lines electrically to the COF, wherein
the scan lines are directly connected to the chip on a first line in parallel with
an extending line from the COF through the scan line connection lines formed on the
COF at both sides of the display panel.
[0013] Preferably, the scan line connection lines are straightly connected to the scan lines
at both sides of the display panel corresponding to the first line and the data line
connection lines are connected to the data lines extending from both sides of the
display panel corresponding to the second line. Also, a substrate material of the
COF is one of glass and plastic.
[0014] In another aspect of the present invention, a display device using a COF includes
a display panel, the COF having a connection part on which the display channel is
placed and a chip part on which a chip is placed, data and scan lines extending from
the display panel, scan line connection lines on the connection part,- the scan line
connection lines connecting the scan lines electrically to the COF, and data line
connection lines on the connection part, the data line connection lines connecting
the data lines electrically to the COF, wherein the scan lines are straightly connected
to the COF through the scan line connection lines at both sides of the display panel
on a first line in parallel with a direction extending from the COF, a portion of
the data. lines extends toward the chip from both sides of the display panel corresponding
to a second line in a direction different from the extending direction of the COF,
and the other portion of the data lines extends toward the chip from both sides of
the display panel corresponding to a second line in a direction different from the
extending line of the COF and is connected to the COF through the data line connection
lines.
[0015] In a further aspect of the present invention, a display device using a COF includes
a display panel, a COF having a connection part on which the display channel is placed
and a chip part on which a chip is placed, data and scan lines extending from the
display panel, scan line connection lines on the connection part, the scan line connection
lines connecting the scan lines electrically to the COF, and data line connection
lines on the connection part, the data line connection lines connecting the data lines
electrically to the COF, wherein the scan lines are straightly connected to the COF
toward the chip through the scan line connection lines at both sides of the display
panel on a first line in parallel with an extending direction of the COF, and the
data lines are connected to the COF through the data line connection lines from both
sides of the display panel on a second line in a direction different from the extending
direction of the COF.
[0016] Preferably, the scan line connection lines extend straightly on the first line and
the data line connection lines form a curve with a predetermined angle so as to extend
from the first line to the second line. The predetermined angle is 90°.
[0017] It is to be understood that both the foregoing general description and the following
detailed description of the present invention are exemplary and explanatory and are
intended to provide further explanation of the invention as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The accompanying drawings, which are included to provide a further understanding
of the invention and are incorporated in and constitute a part of this application,
illustrate embodiment(s) of the invention and together with the description serve
to explain the principle of the invention. In the drawings:
FIG. 1 illustrates a diagram of a display device using a COF according to a related
art;
FIG. 2 illustrates a diagram of a display device using a COF according to a first
embodiment of the present invention;
FIG. 3A illustrates a diagram of a display device using a COF according to a second
embodiment of the present invention;
FIG. 3B illustrates a diagram of a COF structure according to a second embodiment
of the present invention;
FIG. 4A illustrates a diagram of a display device using a COF according to a third
embodiment of the present invention;
FIG. 4B illustrates a diagram of a COF structure according to a third embodiment of
the present invention;
FIG. 5A illustrates a diagram of a display device using a COF according to a fourth
embodiment of the present invention; and
FIG. 5B illustrates a diagram of a COF structure according to a fourth embodiment
of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0019] Reference will now be made in detail to the preferred embodiments of the present
invention, examples of which are illustrated in the accompanying drawings.
[0020] FIG. 2 illustrates a diagram of a display device using a COF according to a first
embodiment of the present invention.
[0021] Referring to FIG. 2, a display device includes a display panel 30, a COF 80 having
a connection part 20 on which the display panel 30 is placed and a chip part 10 on
which a driving chip 60 is placed, and data and scan lines 40 and 50 extending from
the- display panel 30 respectively. Besides, a reference numeral '70' indicates SMD
parts.
[0022] The scan lines 50 are connected straight to the COF 80 from the display panel 30
toward the IC(integrated circuits) chip 60 for driving(hereinafter abbreviated chip)
a display device. Forming curves from the display panel 30 toward the chip 60, the
data lines 40 are connected to the COF 80. And, a substrate material of the COF 80
is glass or plastic.
[0023] The scan and data lines 50 and 40 extend from the display panel 30 attached to the
glass or plastic as the substrate material of the COF 80. The scan and data lines
40 are electrically connected to the driving chip 60 and the SMD parts 70, respectively.
Thus, the driving chip 60 drives the display panel 30.
[0024] Meanwhile, the length of the scan lines between the display panel 30 and COF 80 is
short as the scan lines 50 are straightly connected to the COF 80. On the other hand,
the other length between the data lines 40 and COF 80 is relatively long.
[0025] Generally, an IC chip for driving a current driving type display device uses a constant-current
power supply, whereby a resistance value of data lines has less influence on a driving
voltage of the display device.
[0026] Therefore, in the first embodiment of the present invention, the scan lines 50 of
the display panel 30 which are connected to a connection line(not shown in the drawing)
are shorter than the data lines 40 connected to the other connection line(not shown
in the drawing) of the COF 80 so as to be connected to the COF 80. Thus, the line
resistance of the scan lines 50 in the display device is reduced.
[0027] Besides, the IC chip 60 includes a constant-current power supply supplying the display
device with a constant current. And, the display device includes EL(electro-luminescence),
LED(light emitting diode), FED(field emission display) and the like.
[0028] In this case, a width of the COF 80 is equal to or shorter than that of the display
panel 30.
[0029] FIG. 3A illustrates a diagram of a COF type display device according to a second
embodiment of the present invention, and FIG. 3B illustrates a diagram of a COF structure
according to a second embodiment of the present invention.
[0030] Referring to FIG. 3A, a display device according to a second embodiment of the present
invention includes a display panel 130, a COF 180 having a connection part 120 on
which the display panel 130 is placed and a chip part 110 on which a chip 160 is placed,
and data and scan lines 140 and 150 extending from the display panel 130 respectively.
[0031] The connection part 120 includes data line connection lines 190 and scan line connection
lines 200. The scan line connection lines 200 are formed on the connection part 120
and connect the scan lines 150 electrically to the COF 180. The data line connection
lines 190 are formed on the connection part 120 and connect the data lines 140 electrically
to the COF 180.
[0032] The scan lines 150 are straightly connected to the COF 180 through the scan line
connection lines 200 at both sides of the display panel 130 -on the first line in
parallel with an extension line of the COF 180.
[0033] Forming curves from both sides of the display panel 130 corresponding to a second
line perpendicular to an extending direction of the COF 180, the data lines 140 extend
toward the chip 160 so as to be connected to the COF 180 through the data line connection
lines 190.
[0034] In this case, the scan line connection lines 200 are straightly connected to the
scan lines 150 at both sides of the display panel 130 corresponding to the first line,
while the data line connection lines 190 are connected to the data lines 140 extending
from both sides of the display panel 130 corresponding to the second line. Thus, the
scan line connection lines 200 are longer than the data line connection lines 190.
[0035] A resistance value of the scan lines depends on a metal inside the display device.
If the resistance value is high, it is able to reduce a half of the resistance value
of the-scan lines 150 using the COF 180 shown in FIG. 3B.
[0036] The COF 180 shown in FIG. 3B includes the chip part 110 having the IC chip 160 and
the SMD parts 170 and the connection part 120 to which the display panel 130 will
be attached.
[0037] On the connection part 120, the scan line connection lines 200, which will- be connected
to the scan lines 150 of the display device, are formed as long as a length of the
connection part 120 in a direction of connecting the connection part 120 to the chip
part 110.
[0038] Meanwhile, the data line connection lines 190, which will be connected to the data
lines 140 of the display device, are formed so as to be much shorter than the scan
line connection lines 200.
[0039] As shown in FIG. 3A and FIG. 3B, the connection part 120 of the COF 180 is simultaneously
connected to both sides of the display panel 130 on the first line.
[0040] Namely, a portion of the scan lines 150 starting from the display panel 130 is connected
to one end of the connection part 120 far from the chip part 110, while the other
portion of the scan lines 150 starting from the display panel 130 is connected to
the other end of the connection part 120 adjacent to the chip part 110.
[0041] As mentioned in the forgoing explanation, the scan lines 150 of the display device
are connected to the COF 180 at both sides of the display panel 130, thereby enabling
to reduce the resistance value of the scan lines 150.
[0042] Moreover, the display device according to the. second embodiment of the present invention
uses the scan driving IC chip 160, as shown in FIG. 3A, whereby both sides of the
display panel 130 corresponding to the first line are able to be simultaneously connected
to the chip 160. Therefore, the display panel 130 is driven faster.
[0043] FIG. 4A illustrates a diagram of a display device using a COF according to a third
embodiment of the present invention, and FIG. 4B illustrates a diagram of a COF structure
according to a third-embodiment of the present invention.
[0044] Referring to FIG. 4A, a display device according to a third embodiment of the present
invention includes a display panel 230, a COF 280 having a connection part 220 on
which the display panel 230 is placed and a chip part 210 on which a chip 260 is placed,
and data and scan lines 240 and 250 extending from the display panel 230 respectively.
[0045] As shown in FIG. 4B, the connection part 220 includes data line connection lines
290 and scan line connection lines 300. The scan line connection lines 300 are formed
on the connection part 220 -and connect -the scan lines 250 electrically to the COF
280. The data line connection lines 290 are formed on the connection part 220 and
connect- the data lines 240 electrically to the COF 280.
[0046] In FIG. 4A, the scan lines 250 are straightly connected to the COF 280 through the
scan line connection lines 300 at both sides of the display panel 230 on a first line
in parallel with a direction extending from the COF 280. And, forming curves from
both sides of the display panel 230 corresponding to a second line perpendicular to
the extending direction of the COF 280, a portion 240a of the data lines 240 extends
toward the chip 260 so as to be connected to the COF 280 through the data line connection
lines 290.
[0047] Besides, forming curves from both sides of the display panel 230 corresponding to
a second line perpendicular to the extending line of the COF 280, the other portion
240b of the data lines 240 extend in a direction opposite to the chip 260 so as to
be connected to the COF 280 through the data line connection lines 290.
[0048] As mentioned in the above description, the COF 280 is constructed with the connection
part 220 on which the display panel 230 is placed and the chip part 210 on which the
chip 260 is placed. And, the connection part 220 includes the scan line connection
lines 300 extending on the first line and the data line connection lines 290 also
extending on the first line.
[0049] In this case, the scan line connection lines 300 are straightly connected to the
scan lines 250 at both sides of the display panel 230 corresponding to the first line,
while the data line connection lines 290 are connected to the data lines 240 extending
from both sides of the display panel 230 corresponding to the second line. Thus, the
scan line connection lines 300 are longer than the data line connection lines 290.
[0050] The data lines 240a and 240b starting from the display panel 230, as shown in FIG.
4A, are formed on a substrate(glass or plastic) so as to be separated into two parts
in opposite directions each other. Therefore, a maximum resistance value of the data
lines 240 is reduced to one half of the original resistance value.
[0051] The scan line connection lines 300 and data line connection lines 290b, which will
be connected to the scan lines 250 starting from the display panel 230 and to the
data lines 240b respectively, as shown in FIG. 4B, are formed to-the extent of the
length of the connection part 220. Yet, the data line connection lines 290a, which
will be connected to the data lines 240a, are formed much shorter than the connection
part 220.
[0052] Namely, the connection part 220, as is the same case of the second embodiment of
the present invention, is connected to both sides of the display panel 230 on the
first line simultaneously. The scan line connection lines 300 are formed on the substrate
so that the scan lines 250 are connected to the connection part 220. And, the data
line connection lines 290a and 290b are formed so as to connect the data lines 240a
and 240b separated to extend from both sides of the display panel 230 to the COF 280
on the second line.
[0053] As mentioned in the forgoing explanation, the data lines 240a and 240b split to start
from both sides of the display panel 230 as well, thereby enabling to reduce half
of the resistance value of the data lines 240 as well as half of the resistance value
of the scan lines 250.
[0054] FIG. 5A illustrates a diagram of a display device using a COF according to a fourth
embodiment of the present invention, and FIG. 5B illustrates a diagram of a COF structure
according to a fourth embodiment of the present invention.
[0055] Referring to FIG. 5A, a display device according to a fourth embodiment of the present
invention includes a display panel 330, a COF 380 having a connection part 320 on
which the display panel 330 is placed and a chip part 310 on which a chip 360 is placed,
and data and scan lines 340 and 350 extending from the display panel 330 respectively.
[0056] As shown in FIG. 5B, the connection part 320 includes data line connection lines
390 and scan line connection lines 400. The scan line connection lines 400 are formed
on the connection part 320 and connect the scan lines 350 electrically to the COF
380. The data line connection lines 390 are formed on the connection part 320 and
connect the data lines 340 electrically to the COF 380.
[0057] In FIG. 5A, the scan lines 350 are straightly connected to the COF 380 toward the
chip 360 through the scan line connection lines 400 at both sides of the display panel
330 on a first line in parallel with a direction extending from the COF 380.
[0058] And, the data lines 340 are connected to the COF 380 through the data line connection
lines 390 from both sides of the display panel 330 on a second line perpendicular
to the extending direction of the COF 380.
[0059] As mentioned in the above description, the COF 380 is constructed with the connection
part 320 on which the display panel 330 is placed and-the chip part 310 on which the
chip 360 is placed.
[0060] On the connection part 320 formed are the scan line connection lines 400 extending
straightly on the first line and the data line connection lines 390 forming a curve
with a predetermined angle so as to extend from the first line to the second line.
The predetermined angle in FIG. 5B is 90° .
[0061] In detail, as shown in FIG. 5A and FIG. 5B, the scan line connection lines 400 are
formed so that the scan lines 350 are connected directly to the COF 380 on the first
line. And, the data line connection lines 390 are formed so that the data lines 340
are directly connected to the COF 380 on the second line. Thus, the data lines 340
are arranged in a direction forming a right angle with the scan lines 350.
[0062] The data lines 340 are arranged as a straight-line form like the scan lines 350.
And, the COF 380 shown in FIG. 5B is used. Therefore, the resistance value of the
data lines 340 as well as that of the scan lines 350 is reduced.
[0063] As shown in FIG. 5B, the COF 380 includes the chip part 310 having the IC chip 360
and an SMD part 370 and the connection part 320 having the scan and data line connection
lines 400 and 390 which connect the scan and data lines 350 and 340 starting from
the display panel 330 to the COF 380 respectively.
[0064] Besides, the scan line connection lines 400, as shown in FIG. 5B, having the longest
length of the connection part 320 in order to connect the scan lines 350 to the COF
380 are formed on the connection part 320 in a direction of the first line.
[0065] And, the data line connection lines 390, which will be connected to the data lines
340, are arranged in a direction so as to be bent with a predetermined angle from
the first line to the second line. The bending angle in FIG. 5B is 90°.
[0066] Accordingly, the structures of the display device according to the embodiments of
the present invention enable to reduce the resistance of the scan and data lines starting
from the display panel and further decrease the driving voltage of the display device.
[0067] The forgoing embodiments are merely exemplary and are not to be construed as limiting
the present invention. The present teachings can be readily applied to other types
of apparatuses. The description of the present invention is intended to be illustrative,
and not to limit the scope of the claims. Many alternatives, modifications, and variations
will be apparent to those skilled in the art.
1. A display device using a COF comprising:
a display panel;
a COF having a connection part on which the display channel is placed and a chip part
on which a chip is placed;
data and scan lines extending from the display panel;
scan line connection lines on the connection part, the scan line connection lines
connecting the scan lines electrically to the COF; and
data line connection lines on the connection part, the data line connection lines
connecting the data lines electrically to the COF,
wherein the scan lines are directly connected to the chip on a first line in parallel
with an extending line from the COF through the scan line connection lines formed
on the COF at both sides of the display panel.
2. The display device of claim 1, wherein the chip is a scan driver chip driving the
display panel by connecting both of the sides of the display panel simultaneously.
3. The display device of claim 1 or 2, wherein the scan line connection lines are straightly
connected to the scan lines at both sides of the display panel corresponding to the
first line and the data line connection lines are connected to the data lines extending
from both sides of the display panel corresponding to the second line.
4. The display device of one of the preceding claims, wherein a substrate material of
the COF is one of glass and plastic.
5. The display device of one of the preceding claims, wherein the display device includes
EL(electro-luminescence), LED(light emitting diode), FED(field emission display).
6. A display device using a COF comprising:
a display panel;
the COF having a connection part on which the display channel is placed and a chip
part on which a chip is placed;
data and scan lines extending from the display panel;
scan line connection lines on the connection part, the scan line connection lines
connecting the scan lines electrically to the COF; and
data line connection lines on the connection part, the data line connection lines
connecting the data lines electrically to the COF,
wherein the scan lines are straightly connected to the COF through the scan line
connection lines at both sides of the display panel on a first line in parallel with
a direction extending from the COF, a portion of the data lines extends toward the
chip from both sides - of the display panel corresponding to a second- line in a direction
different from the extending direction of the COF, and the other portion of the data
lines extends toward the chip from both sides of the display panel corresponding to
a second line in a direction different from the extending line of the COF and is connected
to the COF through the data line connection lines.
7. The display device of-claim 6, wherein the chip is a scan driver chip driving the
display panel by connecting both of the sides of the display panel simultaneously.
8. The display device of claim 6 or 7, wherein a substrate material of the COF is one
of glass and plastic.
9. A display device using a COF comprising:
a display panel;
a COF having a connection part on which the display channel is placed and a chip part
on which a chip is placed;
data and scan lines extending from the display panel;
scan line connection lines on the connection part, the scan line connection lines
connecting the scan lines electrically to the COF; and
data line connection lines on the connection part, the data line connection lines
connecting the data lines electrically to the COF,
wherein the scan lines are straightly connected to the COF toward the chip through
the scan line connection lines at both sides of the display panel on a first line
in parallel with an extending direction of the COF, and the data lines are connected
to the COF through the data line connection lines from both sides of the display panel
on a second line in a direction different from the extending direction of the COF.
10. The display device of claim 9, wherein the chip is a scan driver chip driving the
display panel by connecting both of the sides of the display panel simultaneously.
11. The display device of claim 9 or 10, wherein the scan line connection lines extend
straightly on the first line and the data line connection lines form a curve with
a predetermined angle so as to extend from the first line to the second line.
12. The display device of one of claims 9 to 11, wherein the predetermined angle is 90°.